A lot of games had a lot of potential, but critics review the actual thing, not what it could be in the future. I admit he goes a bit overboard sometimes, but the truth is Spore was originally advertised as something much deeper than it ended up being.
Now I bet it will be used as a 'milk cow' for expansions and getting more and more money from costumers who want the game it was meant to be in the first place. The Sims was fine from the beginning and expansions added optional stuff to it, but they might want to take the 10 expansions philosophy to a new level with Spore. Release an unfinished game and later complete it (instead of expand on it) through who knows how many expansions, which of course won't be free.